It occurred to me that there might be a different place to look for heads. I have a book "Rebuilding Your Big Block Ford", John Christ I think, and it lists the heads used on the FE family. There wee a bunch. It is likely that the heads you looking for were used on engines other than the 427. You might look at the 390s which were much more plentiful (1958 - 19740 , 391s (truck version of the 390) the 360 (also truck and Edsel) and the 352. There are Merc versions in the 410s. I have a 390 in my Mustang and I searched a bit for heads. But you don't really want small chamber heads to get the compression up, you're looking for big chamber heads, right.

I scanned the cylinder head listings out the Big Bloc Ford book, There are a lot of choices and they are interchangeable. Note the different chamber volumes could be an importan factor. But 390's were in cars and trucks and they're still plentiful in the scrap yards.

Turns out I've got a '67 F100 that I completely forgot about... I left it back in the woods many years ago. One of those, your parents always hated that car and where you ended up leaving it broken down things, it's parked right next to my brothers Falcon that he set on fire back in the late 70s...

Anyway, it has a 427 in it. The only thing that was ever wrong with that truck is that it was held together with rust that had rusted to itself, the motor was always solid so I'm going to take a trip back in the woods and see what I can find out. It's sat for about 5 years without being run though.

How did you end up with a truck with a 427 in it? 428s were seen in trucks but the 427 is a very different engine. The 428 is a stroked 390. The 427 is over bored and stroked. Its got cross bolted main bearing caps and the oil galleries (2) are on the side of the block and not down the center. That's why they call them "side oilers" and that's why they are so prized the people will buy whole boats to get just the side oiler blocks. The side oiler can't have hydraulic lifters but it can have the overhead cam heads. "Camers" thy're called and make a lot 0f HP. NASCAR banned the "cammer" before they could race it. They hit the drag strip hard.

Let me know what's in your truck. My guess is that its a 428. CC did use the 428 in the later 60s. It was a pretty subtle shift but the 427s were getting to expensive to build. The key is the oil galleries on the side of the block.

The 427 marine motor is a parts bin engineering job by Ford and Chris Craft. They used the royal 427 cross bolted block of racing fame, a fine cast iron crankshaft, low compression pistons, a low rise torque-prone intake from the 352 and 390 series, a RV truck cam, and generic 352 and 390 cylinder heads. The C7JE head is very little different than most common FE heads found on the 390 motors, and they should be quite plentiful. Here is a very detailed photo documentation of the marine 427 head.